Oestrus Ovis Larvae Research Articles

Oestrus ovis in Sheep in Krishna District, Andhra Pradesh

Oestrosis, caused by larvae of Oestrus ovis, is an obligatory myiasis of sheep and goats, identified as a significant problem in small ruminants globally. The present study is aimed to focus on gross lesions and phenotypic characterization of O. ovis larvae and adult flies in infested sheep. A total 123 sheep heads were inspected during routine slaughter or necropsy, for the presence of O. ovis larvae. Of these, 45 (36. 58%) sheep heads were found to harbour the larvae. The infestation rates with respect to breed was highest in non-descript sheep (45%) compared to Nellore Brown (40.27%) and Nellore Jodipi (22.58%), without any significant difference. Age-wise highest prevalence was recorded in older sheep (>1 year, 66.66%), than young ones (< 1 year, 30.39%) with significant difference (ꭓ2=9.877, P=0.002). Gender-wise, ewes showed highest prevalence (37.5%) compared to rams (36.44%) without any significant difference. Gross examination of infested sheep revealed copious nasal discharge, varying from serous to mucopurulent type with inflamed mucous membranes of naso-cranial sinuses. The larval instars (L2 and L3) and adult flies that developed from mature larvae were identified based on stigmal plates and morphological characteristics. In conclusion, oestrosis is common in sheep in Krishna district, Andhra Pradesh, indicating the need for regular surveillance to follow appropriate control strategies.

Morphological and phylogenetic characterization of Oestrus ovis larvae in sheep: Al-Qadisiyah province, Iraq

The fly larvae infect the nasal cavities and sinuses (frontal and maxillary) of sheep, goats, and a range of wild ruminants, forming a disease called oestrosis (Nasal myiasis or nasal bot). The disease is one of the significantly diseases for the Iraqi small ruminant industry that causes detrimental economic losses. The current work was carried out to morphologically- and molecularly-characterize O. ovis larvae collected from sheep in a slaughterhouse in Al-Qadisiyah province, Iraq. The study depended on collecting 20 larvae (at different stages) from 20 sheep from 15 October till 17 December 2020. The morphological examination was done using a stereomicroscope and relying on larval characteristic features, including the posterior end, spiracles, and cephalopharyngeal skeleton. The molecular characterization was performed utilizing polymerase chain reaction (PCR) and partial gene sequencing (PGS) methods of the cytochrome c oxidase subunit I (cox1) gene at 700-bp and 300-bp regions. Morphologically, the first-stage larvae (L1) showed characteristic mouth hooks, while the second-stage larvae (L2) revealed clear terminal stigmas. For the third-stage larvae (L3), the color of body segments and their spines' were the most important features for this larval stage. The PCR showed amplification at both regions 700bp and 300bp, in 8 and 7 isolates, respectively. The PGS revealed 15 different local isolates in genetic level aligned with isolates from Kyrgyzstan, Italy, Spain, and Turkey. This study shows the important strain differences of O. ovis that infect the local sheep in Al-Qadisiyah province, Iraq.

Population diversity of sheep bot fly, Oestrus ovis (Linné, 1758) (Diptera: Oestridae: Oestrinae), using SDS polyacrylamide gel electrophoresis

The study was planned to evaluate the inter, and intra population genetic variation in general protein banding pattern in Oestrus ovis larvae, by using 10% sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS PAGE). The larvae were collected from slaughtered goats head from five different locations (AAS, PN, LA, GM, and BC) of Karachi, Pakistan. The data obtained was subjected to POPGENE (Population Genetic Analysis) software for analysis. The polymorphic loci within populations ranged from 45.45% to 90.91%. Polymorphic loci observed in all populations were 90.91%. The expected heterozygosity observed was 0.182 ± 0.096 in all populations. The chi-square test showed 5 out of 11 loci at H-W equilibrium. The overall fixation index (FST) value was 0.108, showing that the likelihood of subpopulations being differentiated from one another is about 11 percent. The gene flow value (Nm = 2.065) was higher, showing that genes flow occurs between populations. The values of genetic identity were greater, and genetic distance were smaller among all the populations, which means that all the populations were more alike and closer to each other. It was concluded that there was no sympatric and parapatric population differentiation observed among all the population of O. ovis and the populations of the five different locations were not genetically and reproductively isolated from each other.

Answer to September 2021 Photo Quiz.

Microscopic examination revealed the objects to be fly larvae. They were whitish, transparent, oval shaped with a length of 1 mm by 0.33 mm of width (see Fig. 1A in the case presentation [1]), with 12 rows of cuticular spines on both sides (2, 3). The cephalic segment was distinguished with two mandibles curved in a semicircle and two longitudinal appendages (see Fig. 1B in the case presentation [1]). The caudal segment consisted of two tubercles, each containing about 10 curved spines (see Fig. 1C in the case presentation [1]). These morphological characteristics were suggestive of first-instar larvae of Oestrus ovis.

Oestrus ovis larvae in nasal cavity of sheep: A case report

Oestrus ovis larvae in nasal cavity of sheep: A case report

Prevalence of Oestrus ovis Larvae in Slaughtered Sheep of Misan City, Iraq. Rawaa Ghanim Mohammed, Samra Samir Josef, Khalid Jabbar Abed

Prevalence of Oestrus ovis Larvae in Slaughtered Sheep of Misan City, Iraq. Rawaa Ghanim Mohammed, Samra Samir Josef, Khalid Jabbar Abed

The Infestation Study of Oestrus ovis L. 1761 in Sheep of Al-Amara Region, Maysan Province, South of Iraq

362 heads of sheep obtained (in multiple visits) from the central slaughterhouse and the sheep abattoir at Al-Amara region (Maysan, South of Iraq) between November 2016 and March 2017 were examined for the detection of Oestrus ovis larvae for the first time in this region. Sheep heads were examined by dissecting them longitudinally, the sheep were of local breed. Of the 362 heads, 296 (81.8%) were infested with O. ovis larvae. O. ovis larvae were observed recorded in both sexes and all age groups in different temperature ranges (low, medium and high) during the research period. A total of 985 larvae were collected. The overall infestation intensity (IN) was 5.443% L/H with a range of 2-8 larvae per infested head of sheep (L/Hs). The infestation of larval in the infested sheep was 54.14% in low- temperature weather, while 100% in relatively high- temperature weather. March showed the highest infection intensity, while January showed the lowest infection intensity. The novelty of the current study is to conduct the research in an area that totally different from what has been studied before in Iraq in regards to the geographical location and the climate conditions.

External ophthalmomyiasis by Oestrus ovis larvae.

External ophthalmomyiasis by Oestrus ovis larvae.

External ophthalmomyiasis by sheep botfly – a report from Sirmaur hills

Introduction. Myiasis is caused by larvae of flies infesting animal or human tissues and organs. Aim. In this report we present 2 cases of external ophthalmomyiasis by sheep botfly. Description of the cases. We report a case of two patients who presented with a history of foreign body sensation in the left and the right eye respectively. Slit lamp examination revealed larvae of Oestrus ovis (sheep botfly). In both cases, there was no contact history with sheep or goats. Signs of conjunctival inflammation and corneal involvement were absent in both cases. In most of the previous reports, corneal and conjunctival inflammation was present. Conclusion. Treatment for external ophthalmomyiasis is based on larvae removal and application of topical antibiotics and steroids.

Ophthalmomyiasis Caused by Oestrus ovis

Ophthalmomyiasis externa refers to the involvement of external surface of eyes by the larvae of dipterous flies. We here describe case of external ophthalmomyiasis wherein larvae (five in number) were removed by using forceps under local anaesthesia and identified as larvae of Oestrus ovis. J Microbiol Infect Dis 2019; 9(4):161-163.

Rhinomyiasis by Oestrus ovis in a tourist returning from Corsica.

In the Mediterranean basin, one of the most important agents of myiasis is Oestrus ovis Linnaeus 1758 (Diptera, Oestridae). Herein, we report a rare case of nasal myiasis with a secondary infection complication in a patient from northern Italy who had been visiting Corsica. A healthy, 39-year-old Italian woman spent 2 weeks of vacation in Corsica in June 2018. During her stay, she suddenly felt a foreign body inside her nose, followed by cough, pain, burning at the pharyngeal level, cephalalgia, and nasal congestion with secretions from the nostrils. The clinical examination showed a hyperemic and irritated mucosa and endoscopic examination of the patient's nose and right maxillary sinus revealed three tiny mobile larvae, morphologically and molecular identified as L1 instar larvae of Oestrus ovis. The patient's infestation was probably imported from Corsica, as Mediterranean islands are ideal geographical areas for the development of O. ovis, and the timing of infestation match with the period of O. ovis larviposition. Although rhinomyiasis is rare, it should be considered in people returning from abroad presenting with an acute-onset and foreign body sensation in the nose.

The global and regional prevalence of oestrosis in sheep and goats: a systematic review of articles and meta-analysis

BackgroundOestrosis, caused by the larvae of Oestrus ovis, commonly known as sheep nose bot, is an obligatory cavitary myiasis of sheep and goats. Oestrus ovis is a widespread parasite, but little is known about the prevalence of oestrosis at the global and broad geographical levels. The present study aimed to explore the epidemiology of oestrosis at the global and regional level to estimate prevalences and their associated factors using a systematic approach. This is, to the author’s knowledge, the first meta-analysis of oestrosis in sheep and goats.MethodsPublished articles were obtained from nine electronic databases (PubMed, CAB s, Web of Science, Scopus, UCB library, Medline, Biosis Citation Index, Indian journals and Google Scholar) reporting the prevalence of O. ovis in sheep and goats from 1970 to 2018. Pooled prevalences were estimated using a random effect meta-analysis model.ResultsSixty-six studies were eligible, and data from 40,870 sheep and 18,216 goats were used for quantitative analysis. The random effect estimated prevalence of oestrosis at the global level in sheep was 51.15% (95% CI: 42.80–59.51%) and in goats was 42.19% (95% CI: 33.43–50.95%). The pooled prevalence estimates for Africa, Asia, Europe and the Americas were 47.85% (95% CI: 36.04–59.66%), 44.48% (95% CI: 33.09–55.87%), 56.83% (95% CI: 48.92–64.74%) and 34.46% (95% CI: 19.90–49.01%), respectively. Heterogeneity (I2 > 80%) was detected in most pooled estimates.ConclusionsOestrosis is highly prevalent in many geographical regions of the world, especially in Europe and Africa. Factors that contribute to the pooled prevalence estimate of oestrosis need to be emphasised in any survey to estimate the true prevalence of oestrosis. Furthermore, there is a need for immunisation or implementation of other preventive measures to reduce the burden of oestrosis in sheep and goats and to improve the health and welfare status.

Ophthalmomyiasis externa: A case report

Purpose: To report an unusual case of ophthalmomyiasis in a healthy individual from western part of India. Materials and Methods: A 23 years old patient with complaints of redness, severe burning sensation, foreign body sensation and excessive lacrimation in his right eye was examined and diagnosed with ophthalmomyiasis caused by larvae of Oestrus ovis. The patient was successfully treated with combination of Antibiotic and Steroid through topical route. Results: A 23 years patient with presence of larvae was immediately examined and larvae’s were removed and sent for identification. The organisms were found to be Oestrus ovis, the patient was treated with topical Tobramycin 0.3% combined with fluorometholone 0.1%. The complaints resolved completely with no ocular or systemic associations on further investigations. Conclusion: This is one of the uncommon condition in urban areas. The most common organism causing ophthalmomyisis is Oestrus ovis. Oestrus ovis is found in sheep and goat, humans are the accidental hosts and treatment should be aimed to immobilize and removal with secondary treatment of symptoms. Keywords: Larvae, Oestrus ovis, Ophthalmomyiasis externa.

Oestrus ovis external ophtalmomyiasis: a case report in Burgundy France

BackgroundExternal ophtalmomyiasis (EOM) is a zoonosis related to the presence of Oestrus ovis larvae at the ocular level in small ruminants (i.e. ovine, caprine). In humans, EOM is a rare cosmopolitan disorder, mostly described in warm and dry rural areas in patients living close to livestock areas. In metropolitan France (excluding Corsica), EOM is an exceptional disease with less than 25 cases recorded since 1917.Case presentationWe report a case of EOM in a 19-years old man in the last week of September 2016 in Burgundy.ConclusionThe diagnosis of an EOM in Burgundy, a French region described as cold and humid, is surprising and could be due to a more marked climatic warming during the vegetative season in Burgundy resulting in the implantation of Diptera of the genus Oestrus sp. in this region.

Ocular external myiasis. A series of cases due to larvae Oestrus ovis in Navarra, Spain

Abstract Objective To report a case series of external ophthalmomyiasis in a region of Spain together with its common epidemiological factors and treatment. Material and methods A presentation is made of four clinical cases of patients with external ocular myiasis caused by Oestrus ovis larvae. Results Ocular myiasis is a parasitic infection by larval stages of flies. It can affect the ocular globe externally and/or internally, with the former being the most frequently found condition. The organism that mainly affects the eyes is the O. ovis larvae. Conclusion Ocular external myiasis is a rare condition that occasionally can occur in humans. In this case series, a common risk factor for infection is established: the previous exposure to livestock and/or agricultural activity. An adequate diagnosis and treatment could avoid the transition from external to internal form, as well as its complications.

Miasis ocular externa. Serie de casos por larvas Oestrus ovis en Navarra

ObjectiveTo report a case series of external ophthalmomyiasis in a region of Spain together with its common epidemiological factors and treatment. Material and methodsA presentation is made of four clinical cases of patients with external ocular myiasis caused by Oestrus ovis larvae. ResultsOcular myiasis is a parasitic infection by larval stages of flies. It can affect the ocular globe externally and / or internally, with the former being the most frequently found condition. The organism that mainly affects the eyes is the Oestrus ovis larvae. ConclusionOcular external myiasis is a rare condition that occasionally can occur in humans. In this case series, a common risk factor for infection is established: the previous exposure to livestock and / or agricultural activity. An adequate diagnosis and treatment could avoid the transition from external to internal form, as well as its complications.

Rearing and measurements of Oestrus ovis larvae and pupae (Diptera: Oestridae) from slaughtered sheep heads in Mosul abattoir -Iraq

Rearing and measurements of Oestrus ovis larvae and pupae (Diptera: Oestridae) from slaughtered sheep heads in Mosul abattoir -Iraq

Spatial modeling of oestrosis in sheep in Guantánamo province, Cuba

Oestrosis is a myiasis caused by larvae of the fly Oestrus ovis (Linné 1761, Diptera: Oestridae) that occurs worldwide. Oestrosis was first reported in Cuba in the middle of the 1990s in the municipality of Imías, Guantánamo province. Determining the spatial pattern and risk factors for the disease might be useful to help explain the disease occurrence and select options for disease surveillance and control. In the present study, the number and distribution of affected premises was shown to have been similar throughout the period studied (2006–2010). The disease was found to occur mostly in the southern and western parts of the province with high dispersion in an east-west direction over the period of study. Three “hotspots” (Getis-Ord Gi*) were identified in the province in which there was an increased risk of disease occurrence. Geographically Weighted Logistic Regression was used to test associations between environmental variables and disease occurrence. Results demonstrated that areas with lower mean annual rainfall, higher mean temperature, and higher sheep density had the highest risk of disease occurrence. High risk areas are mostly located in the western zone (El Salvador, Niceto Pérez and Guantánamo municipalities) and also in the central zone (coast of San Antonio del Sur and Imías). The associations between oestrosis cases and local environmental characteristics varied geographically within the study area. These results might be useful to improve disease surveillance and control. Treatment of animals in these “hotspots”, as well as in other places where the risk is higher should be prioritized to more efficiently reduce the harmful impact of this disease.

Report of a Case of Human Nasal Myiasis Caused By Second Instar Larvae of Oestrus Ovis in CHU Oran: Review of Literature

Myiasis is the invasion of human and animal organs and tissues by dipteran larvae. This is a case report of a human nasal myiasis caused by the second instar larvae of the sheep bot fly, Oestrusovis. The cases of human myiasis at Oestrusovis are accidental and rare, mainly affecting the eyes. In the literature, there are only sporadic reports of nasal myiasis. We present a new case of nasal myiasis caused by the second instar larvae of Oestrusovis in a 29-year-old male patient, originally from OuedRhiou in the west of Algeria, whois a medical doctor suffering from signs of rhinosinusitis.

S10 Plastination Technique for Preservation of Parasites: the case of Oestrus ovis larvae

S10 Plastination Technique for Preservation of Parasites: the case of Oestrus ovis larvae